synchrouns the account with IMAP

Question

Hi All

my outlook profile handles two accounts one is of exchange and another one is of  IMAP. Out of these  two accounts I want to sync with  IMAP account in certain cases only(like when system  is idle or when exchange is offline)

For achieving  this I have created an Outlook Add in that handles Syncstart event, when sync start is fired  I am just stopping that by  Stop() method of Sync object.
 
I have tried below code but  was not able to stop the sync. Can anybady help me on this.

private NameSpace ns;
ns = ThisAplication.Session;
private Microsoft.Office.Interop.

Outlook.SyncObjectClass mySyncObject;

public void OnStartupComplete(ref System.Array custom)
{
 mySyncObject = (SyncObjectClass)ns.SyncObjects[1];
 mySyncObject.SyncStart += new Microsoft.Office.Interop.Outlook.SyncObjectEvents_SyncStartEventHandler(mySyncObject_SyncStart);
}

private void mySyncObject_SyncStart()
{
       ns.SyncObjects[1].Stop();
}

Thanks in advance.